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| author | s-ol <s-ol@users.noreply.github.com> | 2020-06-03 10:50:20 +0000 |
|---|---|---|
| committer | s-ol <s+removethis@s-ol.nu> | 2025-03-02 14:24:49 +0000 |
| commit | 2a7d979226e98617623b550f207cec0e113ff04d (patch) | |
| tree | 0e9f2d2c36897af3a2569f287296928ba3bb9cf3 /docs/guide/evaltime-and-runtime.md | |
| parent | add loop/recur (diff) | |
| download | alive-2a7d979226e98617623b550f207cec0e113ff04d.tar.gz alive-2a7d979226e98617623b550f207cec0e113ff04d.zip | |
split guide into guide and reference
Diffstat (limited to 'docs/guide/evaltime-and-runtime.md')
| -rw-r--r-- | docs/guide/evaltime-and-runtime.md | 45 |
1 files changed, 0 insertions, 45 deletions
diff --git a/docs/guide/evaltime-and-runtime.md b/docs/guide/evaltime-and-runtime.md deleted file mode 100644 index e718cf3..0000000 --- a/docs/guide/evaltime-and-runtime.md +++ /dev/null @@ -1,45 +0,0 @@ -So far, `alv` may seem a lot like any other programming language - you write -some code, save the file, and it runs, printing some output. "What about the -'continuously running' aspect from the introduction?", you may ask yourself. - -So far, we have only seen *evaltime* execution in alv - but there is also -*runtime* behavior. At *evaltime*, that is whenever there is change to the -source code, `alv` behaves similar to a Lisp. This is the part we have seen -so far. But once one such *eval cycle* has executed, *runtime* starts, and -`alv` behaves like a dataflow system like [PureData][pd], [Max/MSP][max] or -[vvvv][vvvv]. - -What looked so far like static constants are actually *streams* of values. -Whenever an input to an operator changes, the operator (may) update and respond -with a change to its output as well. To see this in action, we need to start -with a changing value. Number literals like `1` and `2`, which we used so far, -are *evaltime constant*, which means simply that they will never update. Since -all inputs to our [math/+][] operator are *evaltime constant*, the result is -constant as well. To get some *runtime* activity, we have to introduce a -side-effect input from somewhere outside the system. - -The [time/][] module contains a number of operators whose outputs update -over time. Lets take a look at [time/tick][]: - - (import* time) - (trace (tick 1)) - -This will print a series of numbers, incrementing by 1 every second. The -parameter to [time/tick][] controls how quickly it counts - try changing it to -`0.5` or `2`. As you can see, we can change [time/tick][] *while it is -running*, but it doesn't lose track of where it was! - -All of the other things we learned above apply to streams of values as well - -we can use [def][] to store them in the scope, transform them using the ops -from the [math/][] module and so on: - - (import* time math) - (def tik (tick 0.25)) - (trace (/ tik 4)) - -Note that if you leave the [time/tick][]'s *tag* in place when you move it into -the [def][] expression, it will keep on running steadily even then. - -[pd]: http://puredata.info/ -[max]: https://cycling74.com/products/max -[vvvv]: https://vvvv.org/ |
